Astrocyte physiology

Tom Bellamy has recently moved to the University of Nottingham.
His new contact details are as follows:

Dr Tomas C Bellamy
Lecturer in Pharmacology
School of Biomedical Sciences
University of Nottingham Medical School
Queen's Medical Centre
Nottingham NG7 2UH
Tel: +44 (0)115 82 30539
Email: tomas.bellamy@nottingham.ac.uk

Our main interest is in the astrocytes – “star cells” – of the central nervous system. These intriguing cells have long been in the shadow of their more excitable kin, neurons, despite being the most abundant cell type in the CNS. Astrocytes play many essential roles in development and physiology, most of them subordinate to the needs of neurons, such as guiding migrating cells to their final destinations in the adult brain, and maintaining a microenvironment favourable for synaptic and electrical transmission by buffering extracellular ions and supplying metabolic intermediates. They also provide a physical bridge between neurons and the microvasculature, relaying information about synaptic activity to the blood vessels that supply the oxygen and energy needed to sustain network activity.

Perhaps the most interesting development in our knowledge of astrocytes has emerged in the last two decades with the discovery that, in addition to the supporting roles outlined above, astrocytes exhibit complex signalling activity in the form of Ca²⁺ oscillations. Thus, these electrically passive cells have been found to participate in the major function of the brain: information processing. Although much slower than action potential propagation, the spread of Ca²⁺ waves through networks of astrocytes enable these cells to respond to synaptic activity and coordinate the activity of neurons over long distances. A major role of these Ca²⁺ signals is the release of neuromodulators to activate neuronal receptors, coordinating network activity, and modifying synaptic strength. Our work aims to improve our understanding of the roles of neuron-astrocyte communication in brain physiology.